The long-term goal is to improve research methodologies for study of alertness/attention. in humans by means of evoked responses obtained when stimuli are provides-at high repetition-rates. This will be accomplished further development of new techniques, both computerized. and behavioral, needed to demonstrate effects of attention/alertness under these special stimulus conditions. High stimulus rates invoke b, rain functions not present at lower rates, such as G-waves, and may provide indications of "temporal binding" mechanisms within the cortex. The experiments will show that the improved techniques work appropriately and are better than presently-available methods. The improvements may well lead to new advances because these responses cannot be obtained now. The project will also determine the hardware/software requirements necessary to meet the needs of laboratory researchers who will first use these techniques. This research is health-related because it is likely to provide data, unavailable by any other means, about brain functions that can be affected by both normal aging, as well as by disease (such as Alzheimer's).